Exhaust silencer for internal-combustion engines



C. G. PUL-LIN EXHAUST SILENCER FOR INTERNAL} COMBUSTION ENGINES Apr. 7,,1923.

Filed April 12 1920 Patented Apr. 17, 1923.

UNITED STATES CYRIL G. PULLIN, OF ISLEWORIH, ENGLAND.

EXHAUST SILENCER FOR INTERNAL-COMBUSTION ENGINES.

Application filed April 12, 1820. Serial No. 373,038.

To all 107mm 2'25 may concern:

Be it known that 1, cm GEORGE PULLIN, a subject of the King of GreatBritain, residing at Isleworth, Middlesex, England, have inventedcertain new and useful Improvements in or Relating to Exhaust Silencersfor Internal-Combustion Engines, of which the following is a specification.

This invention relates to exhaust silencers for internal combustionengines and has particular reference to that type of engine working onthe two-stroke principle.

The silencing of a small two-stroke petrol engine is an entirelydifferent proposition to that to be dealt with in a four-stroke cycleengine. On the four-stroke cycle engine the exhaust is expelled by thepositive stroke of the piston, which practically expels the exhaust gasfrom the cylinder, and further allows the use of a silencing meanshaving a heavy internal resistance to the passage of the gas.

On a tw0-stroke cycle engine, the exhaust is expelled from the cylinderby the relatively feeble blast of the incoming charge; to obtaintherefore the required cooling and the maximum silencing effect for theen gine it is necessary quantity of fresh uel to enter the cylinder,that is, the exhaust and silencing arrangement must be as free aspossible.

Now according tothe present invention I provide a silencer in which theinlet for the exhaust gases opens into the large end of a taperingchamber, the gases being then converged by the tapering contour of thechamber, whereon a high velocity for the gases is obtained, the gasesthen being directed into the large end of a second tapering chamber andso on through a required plurality of compartments taperedlongitudinally and disposed so that the large end of the firstcompartment adjoins the exhaust connection and the smaller end of thesame compartment connects with the large end of the next compartment,the outlet pipe of the cylinder communicating with the small end of thelast of said compartments.

One construction of exhaust silencer embodying the present invention isillustrated by way of example in the accompanying drawings, in whichFig. 1 is a perspective view of the silencer, Fig. 2 is a perspectiveview of the member (detached) which dito allow the maximum vides theinterior of the silencer into compartments, and Fig. 3 is a View of theend cap of the silencer.

In the construction here illustrated the silencer 1 comprises twotapering compartments 2 and 3 formed by the single V-shaped one-piecebaffle 4 disposed within the rec.- tangular body of the silencer 1, andthis baffle piece at is so disposed therein as to leave a third narrowchamber or compartment 5 between one of its limbs and the wall of thebody of the silencer.

The baffle plate 1 is fixed in position in the silencer body by anyconvenient means 1inch as for instance by welding it to the Ifito thelarge end of the first compartment'2 there leads the inlet pipe 6 forthe introduction of the exhaust gases, which on entering the taperingchamber 2 proceed to the narrow end thereof, and then pass throughperforations in the end of one limb of the V-shaped baffle and enter thelarge end of the second tapering compartment 3. The gases again proceedto the narrow end of this chamber and pass out by way of theperforations 8 in the adjacent end of the second limb of the V-shapedbaflle, into the chamber or compartment 5 between the sine of thesilencer body and the bafiie.

From the narrow chamber 5 the exhaust gases pass out of the silencer byan opening or slit 9 made in the cap 10 which fits over the end of thesilencer body 1. This cap is secured to the body by means of a bolt 11passing through eyes 12 in opposite flanges of the cap 10 and throughholes in the ends of opposite sides of the body 1 and bolt 11 is securedin position by a nut 16. The bolt 11 also passes through the ends of theV-shaped baffle 41:.

Externally of the bolt 11 there is arranged a sleeve 17 which serves asa distance piece between the opposite sides of the body 1, and thissleeve 17 is also held in position by means of a short eye bolt 13 whichpasses through a hole 18 in the head of the cap, the eye 14 of the boltembracing the sleeve 17, and has a wing nut 15 screwed over its outerend tight down on the cap 10.

The cap above described may be fitted to either end of the silencer, andit facilitates cleaning or inspection of the silencer, being easilyremovable.

I claim:

1. An exhaust silencer for internal combustion engines comprising acasing, a battle thereindividing the casing internally into two chamberseach with'awide end 'and'a narrow end, the wide end of one chamberadjoiningthe narrow end of the other, a

port a'dmittingiexhaus t gases to the wide 'end of one chamber and aport between the narro w end ofthat'chamber and the wide end oftheadjoining chamber.

3. An exhaust'silencer for internal combnstion' engines comprising acasing, a V- 'shaped bafiie thereinso disposed that 1t d1- vides'thecasing internally into three chambers, two of which each have a wide endand a narrow end, the wide end of one chamber adjoining the nar'row' endof the other, a port admitting. exhaust gases to the wide end ofonechaimber, a port between the narrow end of that chamber and the wideend o f'the adjoining chamber, and a port from ,the narrow end ofthesecond chamber into the third chamber.

LAn exhaust silencer for internal combustionengines comprising a casing,a V- shaped baffle therein disposed with one limb oblique to theadjoining side of the casing and the second limb substantially parallelto the opposite side or" the casing, and dividing the casing internallyinto three chambers, two tapering and one substantially of evensectional area throughout.

5. An exhaust silencer for internal combustion engines comprisingacasing, bafiies therein dividing the easing into three chambers two ofwhich are tapering and a detachable cap over one end of the casinghaviing an opening in it through which the gases 7. An exhaust silencerfor internal "com-" bustion 1 engines comprisinga casing, a i V- shapedbafiie therein, so'disposedthat the casing is divided into threecompartments, two adjacent tapering compartments, and-a thirdofsubstantially even sectional area throughout port admitting exhaustgases to the wide 'end ofone tapering compartment, openings in saidbaflle connecting the smaller end of the last mentioned taperingcompartment to the large'end of the other tapering compartment openingsin the said battle connecting the'smaller end of the said other taperingcompartment with the third compartment of even sectional area, adetachable cap on'the outlet end' 'of said casin-g, means adapted tosecure the caps to the casing, spacing 'means adjacent the capbetween'the opposite walls of the casing, and an outlet opening insaidcap registering with the outlet end of said compartment of "evensectional area.

In te'stimony'whereof I aflix my signature.

CYRILv G. PULLIN.

